# frozen_string_literal: true

module ActiveStorage
  # Decorated proxy object representing of multiple attachments to a model.
  class Attached::Many < Attached
    ##
    # :method: purge
    #
    # Directly purges each associated attachment (i.e. destroys the blobs and
    # attachments and deletes the files on the service).
    delegate :purge, to: :purge_many

    ##
    # :method: purge_later
    #
    # Purges each associated attachment through the queuing system.
    delegate :purge_later, to: :purge_many

    ##
    # :method: detach
    #
    # Deletes associated attachments without purging them, leaving their respective blobs in place.
    delegate :detach, to: :detach_many

    delegate_missing_to :attachments

    # Returns all the associated attachment records.
    #
    # All methods called on this proxy object that aren't listed here will automatically be delegated to +attachments+.
    def attachments
      change.present? ? change.attachments : record.public_send("#{name}_attachments")
    end

    # Returns all attached blobs.
    def blobs
      change.present? ? change.blobs : record.public_send("#{name}_blobs")
    end

    # Attaches one or more +attachables+ to the record.
    #
    # If the record is persisted and unchanged, the attachments are saved to
    # the database immediately. Otherwise, they'll be saved to the DB when the
    # record is next saved.
    #
    #   document.images.attach(params[:images]) # Array of ActionDispatch::Http::UploadedFile objects
    #   document.images.attach(params[:signed_blob_id]) # Signed reference to blob from direct upload
    #   document.images.attach(io: File.open("/path/to/racecar.jpg"), filename: "racecar.jpg", content_type: "image/jpeg")
    #   document.images.attach([ first_blob, second_blob ])
    def attach(*attachables)
      if record.persisted? && !record.changed?
        record.public_send("#{name}=", blobs + attachables.flatten)
        record.save
      else
        record.public_send("#{name}=", (change&.attachables || blobs) + attachables.flatten)
      end
    end

    # Returns true if any attachments have been made.
    #
    #   class Gallery < ApplicationRecord
    #     has_many_attached :photos
    #   end
    #
    #   Gallery.new.photos.attached? # => false
    def attached?
      attachments.any?
    end

    private
      def purge_many
        Attached::Changes::PurgeMany.new(name, record, attachments)
      end

      def detach_many
        Attached::Changes::DetachMany.new(name, record, attachments)
      end
  end
end